Are you spraying your forehands all over the court? You may be using a stroking motion that is too circular. If that’s the case, the slightest error in timing can cause the ball to fly off your racquet at an extreme angle.
You can improve your accuracy by swinging so that your racquet strings face the intended target area across the net for as long as possible before and through contact with the ball. Try laying back your hand and wrist slightly as you make your stroke – much as you would if you were sliding open a patio door.
You’ll find it much easier to keep your racquet head traveling along a straighter, truer path through contact with the ball. The result will be increased accuracy.